Misspelled Words Search Database is showing the word you input "Duel" is spelled correctly.
Duel: Duel usually refers to a battle between two opponents. "Duel" sounds the same as "Dual". "Dual" usually refers to a pair/tandem with similar components.
Disclaimer: Misspelled Words Search is something I scripted to help myself and others write more efficiently. I don't guarantee correctly spelled words are spelled correctly and incorrectly spelled words are spelled incorrectly. If you use this word search, please use diligence.